To conclude all the enterprises in the cluster have contributed to improve the quantitative performance and cluster as a whole.... The Chennai also called as Detroit of India due to its Automotive Industry presence producing over 40% of the India’s Vehicle and Components. The objective is to study on the Quantitative Performance of Chennai Automotive Industry Cluster before (2001-02) and after the CDA (2008-09)? During 2001-02, the Chennai Automotive Industry Cluster(CAIC) consists of Ambattur, Thirumalizai and Thirumudivakkam Industrial Estate located in Chennai had faced problems on infrastructure, technology, procurement, production and marketing. During diagnostic study it is found that there is need for Cluster Development Approach(CDA) for these Industries. The methodology adopted is collection of primary data from 100 ACI using quantitative questionnaire and analysing using Correlation Analysis(CA), Regression Analysis(RA), Fried man Test(FMT), and Kruskall Wallis Test(KWT).